Heat exchanger



D. E. FIELDS HEAT EXCHANGER April 23, 1940.

Filed Dec. 9, 1938 2 Sheets-Sheet l April 23, 1940. D. E. FIELDS HEATEXCHANGER 2 Sheets-Sheet 2 Filed Dec. 9, 1938 INVENTOR M kW ATTORNEY 8 M.mm a .w a v a Patented Apr. 23 1940 UNITED STATES PATENT OFFICE 3Claims.

The invention relates to heat exchangers of the horizontal type andwherein the tubes are relatively long between the headers and aresubject to a wide range of expansion and contraction, and has for itsobject to provide a sag brace structure for the tubes, so constructedand arranged that parts thereof may be removed for allowing the removaland replacement of tubes when they become damaged.

A further object is to provide-transversely extending rollers carried bythe exchanger frame and rotatably mounted in the frame and on which thetubes rest, and which rollers have a rolling contact with the tubes,thereby reducing the wear on the tubes to a minimum, incident to theirmovementwhen they contract and expand.

A further object is to provide vertically disposed removable spacers forthe groups of tubes in vertical planes, and which spacers are detachablymounted as well as the rollers, thereby allowing tubes to be easilyremoved and replaced.

A further object is to form the spacers from U-shaped members, adaptedto arch the tubes and rollers where they intersect, and toprovide aremovable member connecting the arms of the spacers for holding thespacers in place. v

A further object is to so construct the sag brace whereby the rollersmay be removed from the exchanger frame at an angle other than a rightangle, thereby allowing the disassembling of the brace, or assemblingthereof whenthe exchanger is in a relatively small tank orreceptaclewhere room is limited.

A further object is to formthe U-shaped members from spring material,the arms of which are notched to be received in apertures of theretaining plates when the arms are sprung together.

With the above and other objects in view the invention resides in thecombination and arrangement of parts as hereinafter set forth, shown inthe drawings, described and claimed, it being understood that changes inthe precise embodiment of the invention may be made within the scope ofwhat is claimed without departing from the spirit of the invention.

In the drawings:

Figure 1 is a perspective view of one end of a conventional form of heatexchanger showing the sag brace applied thereto.

Figure 2 is an enlarged perspective detail view of a plurality of tubesextending across the rollers and showing one of the U-shaped membersthereon.

Figure 3 is a side elevation of one of the U- shaped members.

Figure 4 is a detail plan view of a portion of the tubebundle.

Figure 5 is a detail perspectiveview of the notched end of one of thearms of the ;U-shaped member, showing the same in any aperture of aportion of one of the retaining plates.

Figure 6 is a plan view of one end of a tank and one end of an exchangertherein, showing the method of removing a sag brace therefrom.

Figure 7 is a horizontal sectional view through one of the supportingbars showing the angular positioning of a sag brace for removing thebrace therefrom.

Heat exchangers of the present type are usually housed in towers orsubmerged tanks Where space is limited, consequently when any of thetubes leak it is extremely difiicult to remove the tubes forrepairorreplacement purposes without removing the exchanger from thetank, because all the tubes are tied together at intervals to form acomplete unit having heads at the ends thereof, one of which is shownfor purposes of illustration and designated by the numeral I.

In the drawings, the tubes 2 are arranged in what is known as the squarepitch arrangement, which is vertical plane arrangement, one above theother, however it is to be understood that the brace hereinafter setforth may be used in connection with offset tubes which are tubes offsetfrom one another in angular alinement, an arrangement called angularpitch. The heads I are connected together by side bars 3 forming a rigidframe and the tubes 2 connect the heads. The tubes expand and contractduring the operation of the exchanger.

The side bars of the frame, at each side thereof, are connected togetherby vertically disposed roller supporting bars 4 having enlarged rollerreceiving apertures 5 therein.

The apertures 5 are sufiiciently large whereby the rollers 6 may beremoved therefrom by removing the cotter pins 1 at the ends thereof, andthen axially moving the rollers until one end of the rollers is insideone of the members 4, and then the rollers can be swung to an angleother than a right angle to the tubes and removed from the other member4 through the enlarged aperture, as clearly shown in Figures 6 and 7,without engaging the walls of the tank la.

During the expansion and contraction of the tubes the rollers 6 rotatein the enlarged apertures 5, consequently the wear on the tubes isreduced to a minimum, which is not the case where there is a slidingcontact as distinguished from a rolling one, and in which slidingcontact there is considerable wear on the tubes.

To maintain the difierent vertical series of tubes in groups, duringassembly and at other times, U-shaped spacers 8 are provided, whichspacers arch the rollers and tubes diagonally at their points ofintersection. The spacers 8 have their arms 9 downwardly disposed andthe arms terminate in notched ends l0, whicheare received in enlargedapertures II in retaining plates I2. It will be seen, by referring toFigure 3, that the arms 9 normally spring outwardly, and when theirnotched ends are placed through the aper tures II, the plates l2 will beheld in position on the shoulders I3 of the notches. It-; will also be,;

in said supports, U -shaped spacer members arching the intersectingpoints of the rollers and tubes and having their arms on opposite sidesof seen that when it is desired to remove a tube, it will only benecessary to spring in the arms 9 of the spacers, for releasing theretainers I 2 and then the spacers can be removed. After this operationthe cotter keys I areremoved from the ends of the desired rollers 6 andthe rollers are 'axially moved'to'disengage one-of their ends from oneof the members 4, after which.-they swung slightly at their releasedends to the'dotted-line position shown in Figure'fi to allowthe otherends to bemoved inwardly through the other member 4. T J

By this construction the work can be done in the tank without removingthe exchanger from the tank, and the defective tube can be cut out ofthe exchanger and replaced and the sag brace parts again assembled inposition.

From the above it will be seen that a'sag brace is provided, which issimple in construction, and one wherein the parts of the brace-may beeasily disassembled without removingthe' exchanger from a tank, andwhere the exchanger is in a relatively small tank.

The invention having been set forth what is claimed as new and usefulis:

1. The combination with a heat exchanger comprising headers connectedtogether by a plurality of tubes, of a sag brace for said tubes, saidbrace comprising transversely disposed rollers extending between thetubes, supports for said rollers, the ends of said rollers havingbearings in said supports and spacer members U-shaped in form archingthe rollers and tubes at their points of intersection, thereby groupingthe tubes in sections.- H r 2.' The combination .with a heat exchangercomprising headers connected together by a plurality of tubes, of a sagbrace for said tubes, said sag brace comprising transversely disposedrollers extending between the tubes, supports for said rollers, theendsof said rollers having bearings the tubes and rollers and closure platesdetachably connected to the arms of the spacers ben'eath .the rollersand tubes. .3. The combination with a heat exchanger comprising headersconnected together by a p111- rality of tubes, of .afsagbrace forsaidtubes,

.said sag brace comprisingv transversely disposed rollersextendingbetween. the tubes, supports for said tubes, .theends-of saidrollers having bear ings in said supports,,Urshapedsspacergmembersarching theintersecting, portions of the:rollers being maintained on thearms by the spring action thereofand by notched ends of the arms in theapertures of the plates,

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